The AIM-listed company expects to hear shortly from the US Food and Drug Administration the date in 2019 it will complete its review of the drug.

Feraccru already has EU approval, while in Switzerland, the drug can be used for iron deficiency anaemia in adults with inflammatory bowel disease.

In September, Dutch-firm Norgine licensed the product for Europe, Australia and New Zealand.

Through that arrangement, Norgine paid £11mln upfront and will pay up to a further €54.5mln in royalties.

Carl Sterritt, Shield’s chief executive, said the NDA review was a big step forward towards Feraccru, potentially being approved in the USA in 2019.

“Following the licensing agreement we signed with Norgine in September for the commercialisation of Feraccru in Europe, Australia and New Zealand, we are well-funded and are increasingly excited about Feraccru's future.”

House broker Liberum sees the US opportunity for Feraccru to be at least as large as Europe, which means £90m, assuming a 65% chance of approval.

Shield is valued at just £39mln, which still reflects the fall-out following the disappointing data for Feraccru from the phase III trial in March.

Discussions with the FDA followed that trial, which allowed it still to file for approval in the US.

Liberum adds that the cash received from Norgine gives shield 12 months of runway, which should cover the potential approval of Feraccru in the US, the results of the head-to-head study between Feraccru and intravenous iron due in the first quarter of 2019 and also a broader launch by Norgine of Feraccru in Europe.

“The potential for US approval and the potential for a positive read-out from the head-to-head study due in Q1 2019 are being ignored,” believes the broker.

A target price of 80p implies that European sales of Feraccru peak at £100m, which reflects the recent setbacks though this valuation contains nothing for either the US or rest of the world, Liberum added.